WH40k: A Different Betrayal
by DodgeStreaker
Summary: What if Erebus had never been able to successfully corrupt the Warmaster, Horus Lupercal? His faith and trust in the Emperor was too great to break. What if instead...He corrupted the Great Angel, Sanguinius? - Disclaimer: Warhammer 40k (c) Games Workshop
1. Numb

**A/N: So! I honestly don't get around very often to flat out writing too many AUs in full, but this one really took the cake! A couple of days ago, almost a week now, me and Abaddon (yes the Arch-Heretic lol) were chatting up on tumblr about an alternate Heresy AU, and it came down to Sanguinius instead. Now cause I don't feel like fleshing out all the boring details to you, and because a lot of it is still in the WIP section we practically swapped a good portion of the loyalist and traitors around and stuff and what not, and their outcomes and who dies and what not but yeah.**

 **Anyways, I'll be writing these short, pretty much incomplete, and not really revised drabbles and posting them in this single file of a "series" right here. If you would like to contribute to our little Heresy AU, please either contact me (PrayBeforeWeFall) or contact Abaddon (Ask-EzekyleAbaddon) on tumblr! Thank you and I hope you enjoy :)**

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The floor was smooth with a decorated tiled texture that was shown only to be visible as it was glossed over with thick amounts of polish. A soft gleam of shadowed figures reflected off its surface from the weak lighting of the thrashed corridor. Splotches of blood and collected drops of sweat were scattered from floor to ceiling, a handful of blue-green and black armoured bodies littered the ground around to add to the foul messy gore. These halls were without the once familiar golden or pearly white paint theme it once adorned, like the colours had been scraped away with dull knives, smearing clear to the undercoats to reveal a rusty black onyx surface. Rough and horribly scratched at, they were etched with Chaotic symbols that softly hissed whispers to anyone who dared to listen too carefully.

Plates of once glorious power armour had been ripped free from the security of the under fibers of the connector ribs that lined the thin coils of the underarmour. Their dulled colours of the clad ceramite plates were smashed in, dented, and beaten from the abuse of brutally violent combat. Among them lay the tattered fabric of torn and sliced away bodygloves, the thick material drenched in blood from either the dead or already obtained wounds. Heretical carved rune medallions jingled and clacked against each other and armoured plates loudly, in rushed, swift movements as the two of them clashed.

Their labored breathing was matched prefectly with one another's, like they weren't already synchronized enough as it was; a raging fire burned brightly in the focused gaze of their eyes, a glare that bled way to pure betrayal. If only they hadn't turned their backs on _each other_ , perhaps this outcome wouldn't have ever come to see the light and would have dissipated from the smoke of the fires.

Another lunge was directed towards him as the battle picked back up from its few moments of exhausted relief, the stab was aimed straight to his throat for it was too low for a complete head shot. He swiftly raised his broken chainsword, taking no moment to recognize the burning fatigue that coursed through his muscles; sneering with hatred and anger as the weapon made contact and slapped against the broken teeth of his own.

"You _traitor_ ," his brother hissed venomously at him, practically spitting the words as he jabbed the Xenos polearm that had whispered taint to him at the broken armour that protected him; wishing to cut deeper, further to the bone into his already wounded flesh where the damaged had left him exposed. "How could you betray _**me**_?!"

"I betrayed no one," he scowled back, a snarl catching in his throat as he raised the blade quickly, trying to disarm his once called brother so that he may end this prolonged battle and swiftly. The both of them had already been in a fit of rage when they had learned of each other's conjoined campaigns against each other, it was hardly coincidental that they were here now, fighting, personally lured out to slit each other's throats. "You turned your back on the Imperium, on _me_! I didn't betray anyone!"

Within a continuously shortening distance, gunfire and heavily armoured footsteps could be heard on the advancing approach to their battleground. Astartes, once of kin before there Heresy had begun, now bludgeon what was considered the enemy for newer glories, revenge and spite. All of it lacked honour. The twin Primarchs only continued to rip and cleave at each other, into each other, far more determined to end the other's life before they were to fall.


	2. Lost

**A/N: But...But my Raven dad! Abaddon! When I asked for more plot point ideas I didn't mean for you to make my birb dad upset! Ah ha :) This stuff is really getting good. I'll try to write more often, definitely. Hmmm. Should I do Mortarion or Angron next? They're both Loyalist in this Au so, hmmm...**

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Kiavahr had been lost, more so than the very words could even speak; the planet itself had been completely destroyed by an unknown, experimental weapon forged from the Heretical hands of the traitorous Mechancius who had too fallen to Chaos with their unfortunate brothers. All that remained was the large splintered fragments of the forge world, drifting in their own gravitational pull while Deliverance remained in its lonesome now, mostly intact as it had been cracked and was now just barely habitual, but still a living memory and proof of their persistence to live on. Like a dying will.

However, all that the XIXth Legion had come and learned to call home, regardless of their natural born differences since the massacre of most of their numbers, was taken from them. So stolen from their grasps that it fed the flames of an already burning pyre. From the Drop-Site Massacre on Istvaan V to the well planned and precise targeted attacks on what remained of them since then, the Night Haunter had crossed the line.

What little people they had managed to save were extremely few, the loss worse than tragic, but the Night Lords seemed to have no intent on sticking around and finishing them off after the loss of their world. Like turning away from a fight, to laugh at them behind their backs while they rolled in the dirt. To wait another day to pull at their strings again, it was _sickening_. There was an unruly amount of now orphaned children, siblings or now single children; many wept, others had been completely shocked to muteness, even more were injured and dying. And all the Raven Lord could do was watch in hated silence as his small group of Apothecaries tended to who they could.

"Vincente," he finally addressed the now Chief Apothecary once he had finally finished patching up the last group of survivors in his sted, the Lord tried to swallow the rage that worked up in his throat. He just wanted to _scream_. The Apothecary looked up at him, exhaustion was outlined and ever present in the features of his expression, yet there was a demanding refusal to pursue any type of rest in his scowl. "How many were we able to save?"

The white clad Astarte only gave a soft sigh and a short shake of his head; the Primarch curled his fists as even more hatred boiled inside of him.

"According to the majority of our officers," he began, voice rough from yelling commands and orders around the Apothecarion for a uncounted amount time now. "Deliverance lost more than two-thirds of its population. And we were only able to successfully evacuate a small percentage of Kiavahr's." His answer was uncertain, completely unsure if the numbers he received were correct. They couldn't be sure, not right now.

"How much?"

"Seven percent..."

The normally patient and melancholy Primarch let out a fierce, unhalted snarl, his master crafted lightning claws swiftly sliding out of the sheath-slots of his gauntlets. "When I get my hands on Konrad, I'M GOING TO BEHEAD HIM!" No one dared to speak up against the Primarch's unwavered rage.


	3. Live On

**A/N: I know I said I was going to write something on Angron or Mortarion next, but it came out as Mournival feels instead LOL Opps.**

 **I'm seriously so hooked on this AU and I LOVE IT LOL I should write some Sigismund angst next...LEL But we haven't discussed much on him and Dorn yet XP**

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The New Moon branded member of the broken Mournival sunk down to his knees, the black clad of his armour was smeared with mud, mixed with the blood of both his foes and his own. The rugged hilt of his sword sat in the tight grip of his right hand, yet he could feel his strength depleting as a long lived adrenaline rush was beginning to die off, too much energy had been spent for so long. If only his body could continue to match the motivation of his mind, of his zeal and merciless threats towards their enemies, but he was now just left battered and exhausted, in need of a long rest.

As he sat there on the plates of his knee guards, his red tattered cape billowed behind him. There was ash thick in the air, falling like grey snow. So much had burned, yet there was still more to cleanse. So much more to _purge_. And so little time to do it.

He tried his vox unit once more, and despite the current situation he still hoped, as several well armed, hardly scratched traitorous Blood Angels circled round, surrounding the downed man. His most trusted Sergeant, now promoted to Captain since the Legion had split into four and Loken had taken his respective leadership as this section of the Legion's ' _Mourning Master_ ', Nero Vipus could not be hailed. The channels and codes of his communications network was scrambled, all that was heard was white noise and the mockery of his enemies. And the ones here waited, these traitors, their low bred kind not even fit to slay him, to be rid of his valiant name and take that glory for themselves, but instead to hassle him like a beaten dog. To keep him laying down so that he may be ready for the slaughter.

His gaze darted up at the brisk approach of a newcomer; he recognized the damned armour as it had once been held in glories and tags raised proudly for the Imperium, adorning these once gracious titles only to taunt them. Standing there now before him, Raldoron looked down at him, the former first Captain of the Arch-Heretic, now the one to claim the title with a menacing demeanor, perhaps even more insane than the bastard Azkaellon. The Blood Angel bore no helmet, and he smirked openly down at him, knowing his injuries would be too much for there to be a real fight if he were to lash out.

"You used to be _greater_ , did losing your precious, beloved, Warmaster really break you so much?" The Black Legionnaire snarled at him and the Heretic _tsk_ 'd at him like a parent would to a misbehaving child. "Now hush dog, _Cerberus_ , was it? That _pet name_ you devoted yourself to, Garviel? Changing your name doesn't change your _defeat_ , your _fate_." The grip on his sword tightened once more, and as he went to stand he was shot still with blistering agony has a non-explosive bolter round drilled into his side where his battered armour was exposed to the bodyglove underneath.

Another tsk.

"They say you cannot teach an old dog new tricks, I suppose they're right," the fallen Angel of Blood gestured over another, stepping back as heavy steps brooded forward. The morbid mask that was adorned on Azkaellon's face, the Executioner since his tides turned insane from the death of their Primarch and the wails of the Red Thirst and Black Rage had overtaken him, was painted in gold, dried streaks of blood tears bleed from the visor sockets. "Who will take your place Loken? When we parade your severed head and prove to your worthless split Legion how pathetically easily your Mournival can fall!" Azkaellon's sword raised, and in silence he raised his own, though he already knew that he could not deflect the upcoming blow, he was too weak. This was the end.

As the swing descended he shut his eyes, a soft prayer slipped from his lips and as he did so, the sound of bursting metal filled his auditory senses; shots in the distance, coming closer, faster. Azkaellon had missed him, but he still felt lightheaded. He could make out the familiar calls and cries of brothers so close to him, their different tones ran through his mind, unable to process their names. Maybe he was hallucinating. His blade dropped as he made contact with the soft, rocky soil. His wounds bled where the damage was too much even for his superhuman healing. He laid there for an eternity.

He groaned when he was suddenly lifted up, and he felt his helmeted head press against a much larger clad frame. Faintly he could hear the soft buzz of fully functioning power armour. His entire being was shaken from trauma.

"Garvi?!" There was movement now; it felt like they were running, but he easily surrendered himself to the numbing pain as it crept through him and to his mind. "Apothecary!" It sounded like Abaddon, he couldn't tell. He was too tired to tell. "Dammit! Tarik get a goddamn Apothecary over here **now**! Aximand, tell them to prep a thunderhawk for emergency take off, we need to get him to the Vengeful Spirit, stat!" The commands were all clear, but the replies were muffled, his thoughts hazy at the thought of his closest brothers here with him. Reaching out to him to survive. His duty wasn't yet done.

Loken would later wake, feeling heavily intoxicated from medications, in the Vengeful Spirit's Apothecarion, surrounded by his Mournival brothers. The Arch-Heretic had slipped away.


End file.
